JPS6014578A - Infrared ray image pickup device - Google Patents

Abstract

PURPOSE:To attain a small-sized, lightweight device at low power consumption and to improve the reliability by using plural infrared ray solidstate image pickup elements having different infrared ray spectral sensitivity characteristic so as to image pickup the same thermal ray image of an object thereby obtaining the temperature distribution and absolute temperature value of the object from a picture signal. CONSTITUTION:The infrared ray solid-state image pickup elements 10, 11 and 12 have different infrared ray spectral sensitivity characteristic from each other by infrared ray band pass filters 13, 14 and 15. Then a picture signal I1 of an infrared ray image having lambda1+ or -DELTAlambda1/2 is outputted to a signal processing circuit 16 from the infrared ray solid-state image pickup element 10, a picture signal I2 of the infrared ray image having lambda2+ or -DELTAlambda2 is outputted to the signal processing circuit 16 from the element 11 and a picture signal I3 of the infrared ray image having lambda3+ or -DELTAlambda3 is outputted to the signal processing circuit 16 from the element 12. The signal processing circuit 16 converts the picture signals I1, I2 and I3 outputted from the infrared ray solid-state image pickup elements 10, 11 and 12 into a picture signal I representing the temperature distribution of the object 50, a signal representing the absolute temperature T of the object 50 and a signal representing the radiation factor epsilon of the object 50 and outputs them.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] This invention is a novel system that uses an infrared solid-state camera to detect not only the temperature distribution of an object but also the absolute temperature of the object. Infrared rays (up to 1' infrared device f'7+
It is related to τ.

[Prior art]

In recent years, two-dimensional layouts (r('J, s)1
- Compatible with the infrared irradiation device - A converter unit that outputs all signals into an infrared φl and a signal readout unit that reads out the signal No. 14 output by the infrared light + [& 4M unit An infrared solid-state imaging device with a Schottky junction all-infrared optical conversion unit was developed by Taru and Sakae.In particular, an infrared solid-state imaging device with a Schottky junction all-infrared light conversion unit was developed due to advances in manufacturing technology for semi-integrated circuit devices. This infrared 41S (infrared photography using one element: α is environmental monitoring, night vision monitoring, resource exploration element, τ It has been put into practical use in a variety of applications, such as crystallinity distribution 11i measurements.

In particular, in the industrial and medical fields, there is a strong demand for an infrared imaging device that can obtain the temperature distribution of an object or a human body without contact2).

In order to meet such demands, conventional infrared imaging devices have been constructed using infrared detection elements.

FIG. 1 is a diagram schematically showing all the main components of an example of a conventional infrared trench sweeping device.

In the figure, (1) is a conventional infrared imaging device, (2)
is an infrared ray 41S that is used to capture a heat ray image of
An infrared lens for the bundle, (3) an infrared lens (2) a horizontal scanning mirror that directs the heat rays from the infrared detection point on the surface of the object to be detected in the horizontal direction VCIfiA;
4) is detected through the entire infrared lens (2) and deflected by the horizontal mirror (3), and the image of the object Q is vertically directed from the infrared laser detection point (HL) to 11Iil. 4-
Mirror the vertical movement, t5) 'd Infrared lens (2)
(7) A chopper mirror that chops the heat rays from the infrared detection point on the surface of the object, which is detected by the horizontal scanning mirror (3) and deflected by the vertical scanning mirror (4). (d) An infrared detection element on the surface of the object (7) that is detected through the entire infrared lens (2), deflected by the horizontal short rod mirror (3) and vertical scanning mirror (14), and chopped by the chopper mirror (5). The infrared detection element (7) detects all of the hot rays and outputs electrical signals corresponding to the hot rays, and (7) is a 7-point standard 7-grade field that calculates the absolute temperature value of the object Qβ.

In this conventional infrared imaging device (1), the infrared lens L
2+ (1-) of the surface of the object detected through
The external line detection point is regularly deflected using a horizontal short mirror (3) and a vertical scanning mirror (scanning mirror) to photograph subject 1? When the wedge surface (7) is scanned as shown by the dot-dash arrow (・ζ), the infrared detection element (6) sequentially outputs [0 1
A heat ray image showing the temperature distribution of the photographed object can be obtained from No. a. Also, during the retrace period of the scanning line, the infrared detection element (6) detects the heat from the object -+1ljH! -Detects and outputs an electrical signal and skin! 5 quasi jli & degree black body (7
) can be detected using a chopper mirror (5) and compared with the output electrical signal, the absolute temperature value of the object to be photographed can be determined. However, in order to accurately determine the absolute temperature value of the object (7), it is necessary to set the VC in accordance with the temperature of the environment of the object (7) and the emissivity of the object (7).

However, with this conventional infrared imaging device tl+,
Since the horizontal scanning mirror (3), vertical scanning mirror (1), and chopper mirror (6) are mechanically driven, it takes a long time to obtain a single screen of a thermal image of the object, and the power consumption is low. It has five drawbacks: it is large, its reliability is poor, and the shape of the device becomes large.

On the other hand, infrared Ill! The above-mentioned infrared imaging device that uses all solid-state image sensors does not require a mechanical scanning mechanism, so the device configuration is simple, compact and lightweight, and it is possible to capture thermal images that show the temperature distribution of the object. 1 screen can be obtained at 1 o'clock, low power consumption is 111 hours, and reliability is also controlled at 1 o'clock. but,
In order to be able to examine not only the temperature distribution of the object but also the absolute temperature value of the object, a reference temperature fish body is required.

The existence of this reference γ-accuracy blackbody hinders the miniaturization of the device, increases power consumption, and furthermore, even if the “city #l” is input, it cannot be used unless the temperature of the extremely sub-temperature blackbody is within a specified value. However, the effectiveness of using an infrared solid-state image sensor is significantly impaired.

[Summary of the invention]

The present invention was made for the purpose of eliminating such drawbacks, and the present invention captures the same thermal track image of the object using a plurality of infrared solid-state imaging devices having different infrared spectral sensitivity characteristics. In addition to determining the temperature distribution of the photographic object, the absolute width value of the photographic object can also be determined from the image signals of the photographic object output by the plurality of infrared solid-state imaging probes, without depending on the reference temperature fish body. The present invention provides an infrared imaging device that is compact, lightweight, low power consumption, and highly reliable.2 Fig. 2 is a diagram schematically showing all the main components of an infrared imaging device according to an embodiment of the present invention. , chiru.

In the figure, the same symbols as those of the conventional example shown in Figure 1 (Vc) are equivalent parts. show. (8) is emitted from the subject object...infrared lens (2) an infrared beam splitter that completely transmits part of the heat rays that have been traced and reflects the other part, (9) is emitted from the subject object mark (2) ) and an infrared beam splitter (101) that transmits a part of the heat rays passing through the infrared beam splitter (8) and reflects the other part.
The image is set so that the heat ray image of the object is focused on the main surface of the object by the heat emitted from the infrared lens (2) and reflected by the infrared beam splinter (8). The infrared solid-state imaging element (11) outputs the image signal beam of the axis, and the infrared lens (11) is emitted from the object axis.
2) and the infrared beam frizzer (8) are provided so that the heat ray image of the object axis is focused on the main surface by the heat rays VcL reflected by the infrared beam fritter (9). An infrared solid-state imaging device outputting an image signal I21-+12) is emitted from the object Φ and sent to an infrared lens (2).

The object (7) is provided in such a way that a thermal image of the object (7) is formed on the main surface by the heat rays passing through the infrared beam splitter (8) and the infrared beam sinter (9).
(14) and (I5) are the infrared solid-state image sensor (14), the infrared solid-state image sensor (II), and the infrared solid-state image sensor (121), respectively. The wavelength of transmitted infrared rays provided on the surface is λ□, and the bandwidth is Δλl at λ2 and λ3.
, Δλ2 and Δλ3, (+6)U infrared solid-state image sensor t+01 , :Il
Image signal processing 1 + b l output by l, 021
Step 3 Calculate the image signal of the heat ray image showing the temperature distribution of the photographed object, the signal indicating the absolute temperature T (r) of the photographed object, and the emissivity ε of the photographed object (7). This is a signal processing circuit that outputs a signal indicating .

Next, the operation of this embodiment will be explained.

The heat rays that passed through the infrared lens (2) from the object to be photographed are divided into three directions by the infrared beam sliver +8+, 191K, and the infrared solid-state image sensor (101K is
The infrared band-pass filter 0311C forms an infrared image with a wavelength of λ1 to Δλ1/2 of the object axis, and the infrared solid-state image sensor 1111K λ2±λ2/2
An infrared image with a wavelength of
1K is an infrared band pass filter t+51 K j, which forms an infrared image of the object W at a wavelength of λ3±Δλ3/2. In short, these infrared solid-state image sensors 1d
ol, (ol, (121n, infrared bandpass filter (13), (141, (by 151,
This means that they have different infrared spectral sensitivity characteristics.

Then, from the infrared solid-state image sensor (10), λl±Δλ□
/2 wavelength infrared image image signal ■1 is signal processing circuit 0
λ2± from the infrared solid-state imaging probe (I1)
The image signal 12 of the infrared image with a wavelength of Δλ2 is output to the signal processing circuit 061, and the infrared solid-state imaging probe (12)
An image signal generator 3 of an infrared image with a wavelength of S±Δλ3 is output to a signal processing circuit 061. In the signal processing circuit (16),
Infrared solid-state imaging probe (10), tll), (+
Image output from 21 No. 48 No. 1 + I21 No. 3
k. Based on the principle described below, an image signal generator that indicates the temperature distribution of the object to be photographed, a signal that indicates the absolute temperature value T of the object to be photographed, and a signal that indicates the emissivity ε of the object to be photographed. Convert and output.

Next, we will discuss the principle of combining the image signal function of the object ω, the absolute temperature value T, and the emissivity ε. Here, the absolute rPA
l1J - Temperature of the environment in which object ■ whose value is T and emissivity is ε is placed? If Ta, then the energy of infrared rays R(λ
, T, Ta)y;f(' is given by the formula.

R(λ, T, Ta1=εW(Tl+ (1-ε) W
(Ta), lrI'] The first term on the right side of Equation 19 above is the infrared energy radiated from the object (1) itself, and the second term is the energy of the object ω from the environment at temperature 'ra.
This is infrared energy due to reflection. W in the above @1 term (TIH1 is the infrared energy emitted by a black body at temperature T, and follows the well-known Plack equation below.

%formula% The above [old style 01 and C2I''j constants.

On the other hand, if the infrared spectral sensitivity characteristic of the infrared photoelectric conversion section of the infrared solid-state image sensor is 2A-y(λ), the image signal output from the infrared solid-state image sensor 1(T, Ta)i'j is expressed by the following equation.

I (T, Ta) - A f y (λ) R (λ, T, Ta
)4λ... [■] Y(λ) in the [1llE formula above] is determined by the infrared spectral sensitivity characteristics of the infrared photoelectric conversion section of the infrared solid-state image sensor, and when this infrared photoelectric conversion section is a Schottky junction, Vtd is expressed as below. It will be done.

Y(λ)=(l-λ/2°.)2...J] Here,
λCOU is the maximum wavelength of infrared light that can be converted into light, determined by the height of the barrier of the Schottky junction.

For example, in a Schottky junction formed between platinum silicide and a P-type silicon substrate (hereinafter referred to as "Pt5i-psi Schottky junction"), the value is about λco -5/Im.

Furthermore, 8 in Equation 13 above is a coefficient that does not depend on the wavelength λ of the infrared rays projected onto the infrared photoelectric conversion section of the infrared solid-state image sensor, and is the transmittance of the optical system of the infrared image sensor and the photoelectric conversion coefficient of the infrared solid-state image sensor. and the gain of the optical signal amplification section.

For example, in an infrared solid-state image sensor whose infrared photoelectric conversion section is a Schottky junction, three different wavelengths λ1. λ2. Image signal output by infrared light of λ3 1. Engineering 2. Once we know the process 3, we can determine the temperature Ta of the environment of the object to be photographed, then these (D images (g)
Using I, I2, I3f, Book L [I) -Qv
From equation E, it can be determined that the image signal representing the temperature distribution of the object (7), the absolute temperature value T, the emissivity ε, and the coefficient A are determined.

In this example, the infrared circumferential image sensor +101, t
ll.

(If the infrared photoelectric conversion unit 121 is a Schottky junction, the infrared solid-state image sensor 101, (Ill,
++21 is an infrared band pass filter t+31,
++4), ++51 K L Therefore, different wavelengths λ1. λ2. Since photoelectric conversion is possible only for infrared light of λ3, the signal processing circuit 06) uses the infrared solid-state image sensor tIO+, ! Image signal processing of object ■ output from I11, 021, I? , using I3k,
Can you calculate the above [■] ~ [lV': 1 equation only for the temperature Ta of the environment of the object to be photographed? By setting and carrying out the process, it is possible to output all the image signals indicating the temperature distribution of the photographed object, the absolute temperature value T, and the emissivity ε.

For example, infrared solid-state image sensors tlol, Ill,
If the infrared light conversion part of ++21 is a Pt5i-psi Schottky junction, the Pt5i-psi Schottky junction has infrared spectral sensitivity characteristics mainly in the 3-5/1 m band, which is called the atmospheric window. Dononokusufiluri03).

(141, (151, λ1=3,5μm, λg=
4.0. An interference filter that can transmit infrared rays with wavelengths of 1 m and λ3-4.5/1 m may be used.

Note that in this example, the infrared solid-state image sensor [01.

(11, H) Although the case where the infrared light IF converter is a Pt5i-psi Schottky junction has been described as an example, the present invention is not limited to this, and a Pd5i-psi Schottky junction is used.

(2) It can be applied to other Schottky junctions such as rsi-psi Schottky junctions, or to infrared detection elements other than Schottky junctions that output signals corresponding to the amount of infrared irradiation.

In addition, in this embodiment, an infrared solid-state image sensor (IQ)
rill, (121), infrared bandpass filters H, (+41
, (Although the case where 151k is used has been described, the present invention is not limited to this.
, (14), +151, when at least one of the infrared filters is replaced with another infrared filter having infrared spectral transparency, such as an infrared long-wavelength filter or a short-wavelength filter. Can be applied.

1 friend, this invention is an infrared solid-state image sensor tIO+,
1llll.

The infrared photoelectric conversion section of Q21 is made of a PtSi-psi Schottky junction with different wall thicknesses and a PdSi
The present invention can also be applied to a -psi Schottky junction and an IrSi -psi Schottky junction.

Further, in the above embodiment, a case is described in which three infrared solid-state image sensors having mutually different infrared ray spectral sensitivity characteristics are used, but the present invention is not limited to this. The present invention can also be applied to the case of using two infrared solid-state imaging devices having the same structure. In this case, it is sufficient to set the temperature 'ra of the environment of the KH1 torn object and the emissivity ε of this object.

〔Effect of the invention〕

As described above, the red F-ray imaging device of the present invention includes a plurality of infrared solid-state imaging devices whose infrared photoelectric conversion sections have different infrared spectral sensitivity characteristics, and a plurality of infrared solid-state imaging devices having different infrared spectral sensitivity characteristics. A thermal ray image of the subject object is captured by the element, and image signals of the subject object outputted by each of the infrared solid-state imaging devices are computationally processed to produce an image signal of the thermal ray image indicating the temperature distribution of the subject object. Since it is equipped with a signal indicating the absolute temperature value of the object mentioned above and a signal processing circuit that outputs the signal, there is no need to provide a reference temperature black body, and the camera is compact, lightweight, has low power consumption, and has high reliability. I lean back.

[Brief explanation of the drawing]

FIG. 1 is a diagram schematically showing the main components of an example of a conventional infrared imaging device, and FIG. 2 is a diagram schematically showing the main components of an infrared imaging device according to an embodiment of the present invention. In the figure, lol, flll) and 021 infrared solid-state image sensor, H, 04) and 0ω are band-pass filters (infrared filters) with different infrared spectral transmission characteristics, l1611"j signal processing circuit, - is the object to be photographed. In addition, the same reference numerals in the figures indicate the same or equivalent parts. Agent Masuo Oiwa Figure 1 Figure 2 ■1 44 Procedural amendment (voluntary) December 26, 1939 ν Patent Office Dear Director, 1. Indication of the case: Japanese Patent Application No. 58-448904 2. Name of the invention: Infrared imaging device 3. Part 5: Detailed explanation of the invention in the specification to be amended. 6. Contents of the amendment (1) In the 7th line of page 3 of the specification, the words "being put into practical use" will be corrected to "being put into practical use." Above 44

Claims (3)

[Claims] (1) A converting unit to infrared light 1 which is arranged two-dimensionally on the semiconductor substrate and outputs a signal corresponding to the infrared irradiation light p4VC, and a signal readout unit which sequentially reads and outputs these infrared lights 'N and the signals output by the converting unit. 4a groove? The infrared ray photoelectric converters have different infrared spectral sensitivity characteristics, and the multiple infrared solid-state imaging elements are used to capture the same heat M of the object.
The image signals of the object which are imaged (11) and output by the respective infrared solid-state imaging systems are subjected to StW processing, and the image signals of the heat ray image indicating the temperature distribution of the object are recorded as -. An infrared imaging device comprising a signal processing port for outputting a signal indicating an absolute crystallinity value of a photographic object. (2) Multiple infrared rays 1^1f (front image element infrared 1
Infrared rope photography according to claim 1, characterized in that the infrared spectral sensitivity characteristics of the optical d-conversion section are made to be different from each other with the infrared filters VCL having mutually different infrared spectral transmission characteristics. Device. (3) Infrared beam C of multiple infrared solid state elements
A special feature characterized in that the infrared spectral sensitivity characteristics of the electrical conversion parts are made to differ by VC by making each of the above-mentioned infrared light quasi-conversion parts a Schottky junction having a barrier quality of VcP. - An infrared imaging device R according to claim φ[), item 11τ1.